Given below are two statements:

Statement I: Classical smog is formed when oxides of nitrogen combine with particulate matter especially in summer season.

Statement II: Classical smog reduces atmospheric visibility to a great extent. the of the above statements, choose the correct answer from the options given below:

The correct option is: Statement I is false, but statement II is true.

Explanation of Statement I:
Classical smog (also known as London smog or sulfurous smog) occurs in a cool, humid climate and is a mixture of smoke, fog, and sulfur dioxide (SO₂). It is chemically reducing in nature. In contrast, photochemical smog is formed in warm, dry, and sunny climates when oxides of nitrogen (NO_x) and volatile organic compounds react with sunlight, producing particulate matter like PAN (peroxyacetyl nitrate). Therefore, Statement I is false because classical smog is not formed by oxides of nitrogen combining with particulate matter in the summer season; that description corresponds to photochemical smog.

Explanation of Statement II:
Smog (both classical and photochemical) consists of suspended particulate matter and aerosols that scatter and absorb light. This significantly decreases the transparency of the atmosphere, reducing atmospheric visibility to a great extent and causing hazards for transportation. Thus, Statement II is true.